Three practical criteria of comparison among ordinal preference aggregating rules

The wide availability of methods of aggregation, none of which is generally recognized as being the best, causes a particular difficulty in the preferences aggregation problem. To face this difficulty in the context of selecting aggregation rules, a careful and systematic analysis of the rules seems to be required. This paper attempts to complete a framework for systematic comparison among ordinal preference aggregating methods. Three criteria of comparison, which have a practical character, are proposed. These are: the frequency/intensity of internal inconsistencies, the ability to discriminate the best alternatives, and the complexity of the algorithms. The first two comparative criteria are applied by means of random simulations. The complete comparison framework also includes some theoretical aspects, which will be briefly reviewed here. The three comparative criteria proposed in this paper are used to assess the aggregating rules of Blin, Kemeny, Köhler and Borda. The results, although not exhaustive, show the potential of such an approach for making meaningful comparisons among other aggregating rules.